In the battle among the social networks to attract new users, 2016 will be a banner year for Snapchat. It will grow its user base by double digits, pulling ahead of Twitter and Pinterest in the US for the first time, according to eMarketer’s latest forecast on mobile messaging apps. And the gap will only widen through 2020.

While certain social media companies disclose monthly or daily active users, eMarketer defines a user as someone who logs into an account at least once a month consistently over a calendar year. That means users with multiple active accounts count as only one person in our estimates, which also ignore active accounts such as bots.

This year, Snapchat’s US user base will jump by 27.2% to 58.6 million users. Snapchat’s growth rate far exceeds that of mobile messaging in general—the category as a whole will grow by 16% in the US this year. Meanwhile, Twitter will have 56.8 million users in the US this year and Pinterest will have 54.6 million users. By 2020, Snapchat will add 26.9 million users, about double that of Twitter and Pinterest.